Web sterilization and package forming apparatus



y 1968 F. GOLDSMITH ET AL 3,383,831

WEB STERILIZATION AND PACKAGE FORMING APPARATUS Filed April 5. 1964 INVENTORSZ FRANK GOLDSMITH EDWARD GOLDSMITH BY WWW ATTYS.

United States Patent 3,383,831 WEB STERILIZATION AND PACKAGE FORMING APPARATUS Frank Goldsmith, 1106 Curtis Drive, and Edward Goldsmith, 1108 Curtis Drive, both of Wyncote, Pa. 19095 Filed Apr. 3, 1964, Ser. No. 357,198 4 Claims. (Cl. 53167) ABSTRACT OF THE DISCLOSURE Apparatus for sterilizing a continuously moving web and forming packages therefrom including an enclosed chute through which the web is passed and a heater blower for directing a flow of hot air at a sterile temperature into the chute and along a surface of the web, a roll adjacent the discharge end of the chute for supporting the web and means for heating the roll to a sterile temperature. Additional sterilizing means may be provided ahead of the chute by a flanged roll receiving upwardly extending runs of the web, and means for applying a liquid chemical sterilizing agent to the surface of one of the web runs so that the agent runs down the web surface and accumulates above the web roll to effect a complete wetting of the web surface in contact with the roll.

The present invention relates generally to a method and apparatus for sterilizing paper webs and more particularly to such a method and apparatus for the sterilization of continuously moving paper webs utilized in the packaging of food and dairy products.

Although the present invention may be used in a wide variety of processes and systems requiring the sterilization of a web element, it has been specifically developed for and is herewith presented in connection with equipment for packaging sterile liquid food products such as milk, cream and the like in packages formed from a continuous flat paper web. Packaging systems of the type for which the present invention is particularly well suited are shown for example in US. Patents 2,738,631 and 2,741,079.

Web sterilization arrangements are known in which the web is chemically treated with chlorine, hydrogen peroxide or other sterilizing agents to kill bacteria which may be present on the web surfaces. The chemical treatment step effectively sterilizes the web, but gives rise to the further problem of drying the chemical agent from the web without recontamination thereof. In food packaging processes it is particularly essential that the packaging web be free of the sterilization agent prior to contact with the food products and that further web contamination be prevented during the drying of the web.

It is accordingly a primary object of the present invention to provide a method and apparatus for chemically sterilizing a paper web including means for drying the chemically treated web without recontaminating the surfaces thereof.

A further object of the invention is to provide a method and apparatus for sterilizing a moving paper web by treatment thereof with high temperature sterile air.

Additional objects and advantages of the invention will be more readily apparent from the following detailed description of an embodiment thereof when taken together with the accompanying drawings in which:

FIG. 1 is a side elevational view partly in section of apparatus embodying the present invention shown operatively mounted on a packaging machine;

FIG. 2 is a view taken along line 22 of FIG. 1; and

FIG. 3 is a sectional view taken along line 33 of FIG. 1.

Referring to the drawings, the illustrated embodiment of the invention is shown in conjunction with apparatus "ice 10 for the continuous forming and filling of sealed tetrahedral packages from a flat coated paper web 12 which enters the apparatus 10 at the top thereof as shown in FIG. 1. The partly shown packaging apparatus 10 is a unit similar to those disclosed in the aforementioned patents and includes a housing 14 enclosing the package filling and sealing apparatus. A vertical frame 16 extends above the housing 14 and supports at its uppermost extrerne a flanged web-guiding roll 18. The web 12 descending from the roll 18 is formed into a tubular shape by forming rings 20 and 22. The web is guided into the forming rings in the proper configuration by the vertically extending web guide means 24 mounted on the vertical frame 16 between the roll 18 and the forming rings. A conduit 26 extends into the tubular web from above the forming rings for filling the packages forming within the housing 14.

The illustrated embodiment of the invention includes apparatus 28 for applying a chemical sterilizing agent to a single side of the web and the arrangement broadly designated 30 for drying the web subsequent to the application of the chemical sterilization agent without recontaminating the surface thereof. The elements of the invention as shown in FIG. 1 are located along the upward run of the web 12 which in packaging apparatus of the type illustrated is an open web run serving to transport the web to the top of the frame 16.

Considering the elements of the illustrated embodiment in the order encountered by the advancing web, the web travels from a supply roll (not shown) upwardly into a housing 32 mounted adjacent the apparatus 10. The web passes around spaced flanged rolls 34 and 36 in the housing which provide a horizontal web run 38 along which is operably mounted the perforator 40. The perfiorator is adapted to punch spaced, tabbed holes in the web which serve as pouring outlets for the filled packages. From the roll 36, the web travels upwardly to flanged roll 42 and then downwardly around flanged roll 44 which is disposed within trough 46. The trough 46 is secured to housing 32 by angles 48 and 50 and is provided with a fluid outlet 52 to which is connected conduit 54.

The web travels from roll 44 to the roll 56 spaced directly thereabove. The vertical run 58 of the web extending between rolls 44 and 56 is subjected on one side to a chemical spray from horizontal spray conduit 60 extending across the width of the web and having spaced spray openings 62 in the side thereof facing the web. The conduit 60 is connected with a pressurized source of chemical sterilizing agent such as a chlorine solution.

From the roll 56, the web travels upwardly in an extended run 64 to the flanged roll 18 at the top of the apparatus 10, the run 64 passing through the enclosed drying chute 66 which extends between the rolls 56 and 18. The drying chute as shown in FIG. 3 comprises an elongated U-shaped bottom member 68 and a similar inverted U-shaped upper member 70 which is pivotally secured thereto by hinges 72.

Mounted at the upper end of the drying chute 66 at one side thereof is the heater-blower 74 which is disposed so as to direct a continuous stream of hot air into the upper end of the drying chute through the nozzle 76 passing through the side of the chute. The heater-blower 74 includes a centrifugal blower 78 directing a stream of air into the cylindrical electric heater 80 from which it passes into the chute 66 through the nozzle 76. The heater-blower is supported adjacent the drying chute by bracket 82 attached to the vertical frame 16.

The nozzle 76 directs hot air into a distribution box 84 in the chute 66 which is adapted for passage of the web through the open ends thereof. The distribution box 84 is characterized by curved upper and lower panels 86 and 88 which serve to direct an air flow along the web both upwardly toward the roll 18 and downwardly toward the roll 56. A hot air deflection plate 90 is mounted over the roll 18 by means of brackets 92 attached to the vertical frame 16. The function of the deflection plate will be apparent from the discussion of the operation of the invention set forth below.

For operation, the web is threaded in the manner illustrated around the various flanged rolls, through the distribution box 84 and into the packaging apparatus. The hinged construction of the drying chute 66 permits ready access for threading of the web. The travel of the web is a continuous movement effected by a mechanism inside the packaging apparatus.

The web first passes through the perforator 40 where appropriate holes are punched and tabbed to provide access openings in the containers. The web then travels to the sterilizing agent application area wherein a spray of sterilizing agent is directed from the conduit 60 onto one side of the vertical run 58 of the web. The chemical spray flows down the surface of the run 58 and accumulates above the roll 44 between the flanges of the roll and the web runs. The accumulation of sterilizing agent in this region insures a wetting of the entire web surface with the liquid agent as the web passes around the roll 44. Any excess accumulation of sterilizing agent which may spill over the flanged roll 44 is recovered by the trough 46 and returned to the sterilizing agent supply through the conduit 54.

The wet-surfaced web passes over the roll 56 and into the drying chute 66 through which a rapidly moving flow of hot air is directed by the heater-blower 74 in conjunction with the distribution box 84. The subjection of the web to the hot air flow in the drying chute evaporates the sterilizing agent from the web surface and prevents, due to the high temperature of the air, the recontamination of the web prior to filling and sealing in the packaging apparatus. In this respect, the heater 80 should be adjusted to provide as hot an air flow as is permissible without harming the web. Since temperature above 300 F. are generally considered to be sterile, the temperature of the hot air introduced into the drying chute should be of a temperature substantially above 300 F. to positively insure against recontamination of the web during the drying process and further to expedite the evaporation of the chemical agent. Temperatures as high as 800 F. at the heater-blower nozzle 76 have been successfully used in apparatus of the type illustrated without adversely effecting a paper web of polyethylene-lined Kraft paper construction. The web must, of course, be maintained in continual motion to prevent overheating.

The deflection plate 90 located above the roll 18 serves to direct the hot air flow from the upper end of the drying chute onto the roll 18 to thereby elevate the temperature of the roll to a sterile temperature and thus preclude the possibility of contamination of the web surface by contact with the roll.

The web, on descending into the packaging apparatus 10, is further protected from contamination by a vertically disposed ultra-violet lamp 94 secured to the vertical frame 16. The web, in traveling over the web guide means 24, is subjected to the direct rays of the lamp 94 and immediately thereafter passes through the forming rings 20 and 22 and is transformed into filled packages.

The above described arrangement, by employing a chemical sterilizing agent in addition to a heating arrangement for drying the sterilizing agent which employs a high temperature air flow, provides double insurance against the possibility of web contamination. The use of the sterilizing agent in the first instance provides an effective decontamination of the web surface, and the additional heating arrangement is, of itself, due to the elevated temperatures employed, sufficient to sterilize the web surfaces. Although the combined use of a chemical sterlizing agent and heating arrangement is preferred as illustrated, the use of the chemical sterilizing agent may be omitted and the sterilization of the web accomplished solely by the exposure of the web to the hot air flow in the chute 66. Such treatment of a moving web with hot air at sterile temperatures is a clean and economical manner of providing a sterile web surface, there being no danger of unwanted sterilizing agent inadvertently passing into the filled package as might occur when using chemical sterilization alone.

Manifestly, changes in details of construction can be effected by those skilled in the art without departing from the spirit and the scope of the invention as defined in and limited solely by the appended claims.

We claim:

1. In combination, apparatus for forming packages from a flat continuously moving paper web and filling said packages with a sterile fluid, said web entering said apparatus vertically from above and being formed into a vertical tube into which the sterile fluid contents are introduced, and means for sterilizing said web prior to filling with sterile fluid, said latter means comprising means for applying a liquid chemical sterilizing agent to a surface of the web, and means for evaporating the sterilizing agent from the surface without contaminating the surface, said latter means comprising an upwardly inclined longitudinally extending chute adapted for the passage of the web longitudinally therethrough, means for directing a flow of air at a sterile temperature into said chute whereby the web surface is subjected to the flow of hot sterile air during passage through said chute to vaporize the sterilizing agent while maintaining the web surface in a sterile condition, a roll positioned adjacent the discharge end of said chute to support the web, the web passing from said roll vertically downwardly into said package forming and filling apparatus, and means for directing hot sterile air from said chute onto said roll to heat said roll to a sterile temperature, thus preventing contamination of the web by said roll.

2. Apparatus for sterilizing a continuously moving web comprising means for applying a liquid chemical sterilizing agent to a surface of the web, and means for evaporating the sterilizing agent from the web surface without contaminating the web surface, said means for applying a liquid chemical sterilizing agent to a surface of the web comprising a flanged roll adapted to receive the web with the runs of the web adjacent the roll extending upwardly therefrom, and means for applying a liquid chemical sterilizing agent to the surface of one of the adjacent web runs so that the sterilizing agent flows down the web surface and accumulates above said roll between the roll flanges and the web runs to effect a complete wetting of the web surface in contact with said roll, said means for evaporating the sterilizing agent from the web surface comprising a longitudinally extending enclosed chute adapted for the passage of the web longitudinally therethrough, a heater-blower connected to said chute for directing a flow of hot air at a sterile temperature into said chute, and means in said chute for distributing the hot air along the web surface whereby the sterilizing agent is evaporated from the web surface and the surface is maintained in a sterile condition during passage through said chute by exposure to the flow of hot air at a sterile temperature.

3. Apparatus for sterilizing a continuously moving web comprising a longitudinally extending enclosed chute adapted for the passage of a web longitudinally therethrough, a heater-blower connected to said chute for directing a flow of hot air at a sterile temperature into said chute, means in said chute for distributing the hot air along at least one surface of the web whereby the surface of the web is sterilized during passage through said chute by exposure to the flow of hot air at a sterile temperature, and at least one roll positioned adjacent the web discharge end of said chute for supporting the web, and means for heating said roll to a sterile temperature.

5 6 4. The invention as claimed in claim 3 wherein the 3,055,731 9/1962 Loiiger 21-58 X means for heating said roll comprises the flow of hot air 3,158,886 12/ 1964 Grimes 134-64 X passing from said chute. 3,291,563 12/1966 Mai-tin 2158 X 3,044,885 7/1962 Loehr 167-84 X References Cited 5 v FOREIGN PATENTS Q UNITED TATES PATENTS 831,922 4/1960 Great Britain. 2,348,574 5/1944 Ross 21 92 2,361,350 10/1944 p et 11868 X MICHAEL E. ROGERS, Primary Examiner. 

